Attempt to address missing kernelspec issue (microsoft#3887)

* Potential fix for 3669 KernelSpec enumeration seems to be failing inside of Jupyter

Author: rchiodo

news/2 Fixes/3699.md

@@ -0,0 +1 @@
+Survive missing kernelspecs as a default will be created.

src/client/common/asyncDisposableRegistry.ts

@@ -15,7 +15,9 @@ export class AsyncDisposableRegistry implements IAsyncDisposableRegistry {
  await Promise.all(promises);
  }
 
- public push(disposable: IDisposable) {
- this.list.push(disposable);
+ public push(disposable: IDisposable | undefined) {
+ if (disposable) {
+ this.list.push(disposable);
+ }
  }
 }

src/client/datascience/jupyter/jupyterExecution.ts

@@ -209,9 +209,9 @@ export class JupyterExecution implements IJupyterExecution, Disposable {
  kernelSpec = await this.getMatchingKernelSpec(connection, cancelToken);
  }
 
- // If still not found, throw an error
+ // If still not found, log an error (this seems possible for some people, so use the default)
  if (!kernelSpec) {
- throw new Error(localize.DataScience.jupyterKernelSpecNotFound());
+ this.logger.logError(localize.DataScience.jupyterKernelSpecNotFound());
  }
 
  // Try to connect to our jupyter process
@@ -254,7 +254,7 @@ export class JupyterExecution implements IJupyterExecution, Disposable {
  return result.stdout;
  }
 
- private async getMatchingKernelSpec(connection?: IConnection, cancelToken?: CancellationToken): Promise<IJupyterKernelSpec | undefined> {
+ protected async getMatchingKernelSpec(connection?: IConnection, cancelToken?: CancellationToken): Promise<IJupyterKernelSpec | undefined> {
  // If not using an active connection, check on disk
  if (!connection) {
  // Get our best interpreter. We want its python path
@@ -681,18 +681,23 @@ export class JupyterExecution implements IJupyterExecution, Disposable {
  const kernelSpecCommand = await this.findBestCommand(KernelSpecCommand);
 
  if (kernelSpecCommand) {
- // Ask for our current list.
- const list = await kernelSpecCommand.exec(['list'], { throwOnStdErr: true, encoding: 'utf8' });
-
- // This should give us back a key value pair we can parse
- const lines = list.stdout.splitLines({ trim: false, removeEmptyEntries: true });
-
- // Generate all of the promises at once
- const promises = lines.map(l => this.readSpec(l));
-
- // Then let them run concurrently (they are file io)
- const specs = await Promise.all(promises);
- return specs.filter(s => s);
+ try {
+ // Ask for our current list.
+ const list = await kernelSpecCommand.exec(['list'], { throwOnStdErr: true, encoding: 'utf8' });
+
+ // This should give us back a key value pair we can parse
+ const lines = list.stdout.splitLines({ trim: false, removeEmptyEntries: true });
+
+ // Generate all of the promises at once
+ const promises = lines.map(l => this.readSpec(l));
+
+ // Then let them run concurrently (they are file io)
+ const specs = await Promise.all(promises);
+ return specs.filter(s => s);
+ } catch {
+ // This is failing for some folks. In that case return nothing
+ return [];
+ }
  }
  }
 

src/client/datascience/jupyter/jupyterSessionManager.ts

@@ -48,6 +48,9 @@ export class JupyterSessionManager implements IJupyterSessionManager {
  const spec = kernelspecs[k];
  return new JupyterKernelSpec(spec);
  });
+ } catch {
+ // For some reason this is failing. Just return nothing
+ return [];
  } finally {
  // Cleanup the session manager as we don't need it anymore
  if (sessionManager) {

src/test/datascience/mockJupyterManager.ts

@@ -196,7 +196,9 @@ export class MockJupyterManager implements IJupyterSessionManager {
 
  public startNew(connInfo: IConnection, kernelSpec: IJupyterKernelSpec, cancelToken?: CancellationToken) : Promise<IJupyterSession> {
  this.asyncRegistry.push(connInfo);
- this.asyncRegistry.push(kernelSpec);
+ if (kernelSpec) {
+ this.asyncRegistry.push(kernelSpec);
+ }
  if (this.sessionTimeout && cancelToken) {
  const localTimeout = this.sessionTimeout;
  return Cancellation.race(async () => {

src/test/datascience/notebook.functional.test.ts

@@ -23,7 +23,9 @@ import { JupyterExecution } from '../../client/datascience/jupyter/jupyterExecut
 import {
  CellState,
  ICell,
+ IConnection,
  IJupyterExecution,
+ IJupyterKernelSpec,
  INotebookExporter,
  INotebookImporter,
  INotebookServer,
@@ -721,6 +723,25 @@ plt.show()`,
  }
  });
 
+ runTest('Invalid kernel spec works', async () => {
+ if (ioc.mockJupyter) {
+ // Make a dummy class that will fail during launch
+ class FailedKernelSpec extends JupyterExecution {
+ protected async getMatchingKernelSpec(connection?: IConnection, cancelToken?: CancellationToken): Promise<IJupyterKernelSpec | undefined> {
+ return Promise.resolve(undefined);
+ }
+ }
+ ioc.serviceManager.rebind<IJupyterExecution>(IJupyterExecution, FailedKernelSpec);
+ jupyterExecution = ioc.serviceManager.get<IJupyterExecution>(IJupyterExecution);
+ addMockData(`a=1${os.EOL}a`, 1);
+
+ const server = await createNotebookServer(true);
+ assert.ok(server, 'Empty kernel spec messes up creating a server');
+
+ await verifySimple(server, `a=1${os.EOL}a`, 1);
+ }
+ });
+
  // Tests that should be running:
  // - Creation
  // - Failure